The role of focal adhesion kinase in the TGF-β-induced myofibroblast transdifferentiation of human Tenon's fibroblasts

Genome-wide RNA sequencing of ocular fibroblasts from glaucomatous and normal eyes: Implications for glaucoma management

Primary open angle glaucoma is a leading cause of visual impairment and blindness which is commonly treated with drugs or laser but may require surgery. Tenon's ocular fibroblasts are involved in wound-healing after glaucoma filtration surgery and may compromise a favourable outcome of glaucoma surgery by contributing to fibrosis. To investigate changes in gene expression and key pathways contributing to the glaucomatous state we performed genome-wide RNA sequencing. Human Tenon's ocular fibroblasts were cultured from normal and glaucomatous human donors undergoing eye surgery (n = 12). mRNA was extracted and RNA-Seq performed on the Illumina platform. Differentially expressed genes were identified using a bioinformatics pipeline consisting of FastQC, STAR, FeatureCounts and edgeR. Changes in biological functions and pathways were determined using Enrichr and clustered using Cytoscape. A total of 5817 genes were differentially expressed between Tenon's ocular fibroblasts from normal versus glaucomatous eyes. Enrichment analysis showed 787 significantly different biological functions and pathways which were clustered into 176 clusters. Tenon's ocular fibroblasts from glaucomatous eyes showed signs of fibrosis with fibroblast to myofibroblast transdifferentiation and associated changes in mitochondrial fission, remodeling of the extracellular matrix, proliferation, unfolded protein response, inflammation and apoptosis which may relate to the pathogenesis of glaucoma or the detrimental effects of topical glaucoma therapies. Altered gene expression in glaucomatous Tenon's ocular fibroblasts may contribute to an unfavourable outcome of glaucoma filtration surgery. This work presents a genome-wide transcriptome of glaucomatous versus normal Tenon's ocular fibroblasts which may identify genes or pathways of therapeutic value to improve surgical outcomes.

Synergistic effect of zoledronate and compressive force suppresses proliferation and differentiation of human gingival fibroblasts

We investigated the effects of zoledronate (ZA) and compressive force, separately and in combination, on the proliferation and differentiation of human gingival fibroblasts (HGFs) to verify the mechanism underlying medication-related osteonecrosis of the jaw (MRONJ). The addition of 100 µM ZA markedly inhibited cell proliferation. Expression of type I collagen, fibroblast growth factor 2, and connective tissue growth factor genes, was decreased by ZA and compressive force. Similar results were observed for collagen expression by using Sirius red staining. These results, together with clinical findings that MRONJ is more common in cases with excessive mechanical stress on the oral mucosa, suggest that bisphosphonates such as ZA and mechanical stress may act in conjunction as risk factors for the development of MRONJ by affecting homeostasis of the oral mucosal tissues, including HGFs.

The total iridoid glycoside extract of Lamiophlomis rotata Kudo induces M2 macrophage polarization to accelerate wound healing by RAS/ p38 MAPK/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Lamiophlomis rotata (Benth.) Kudo (L. rotata), a Tibetan medicinal plant, is used to treat "yellow-water diseases", such as skin disease, jaundice and rheumatism. Our previous study showed that the iridoid glycoside extract of L. rotata (IGLR) is the major constituent of skin wound healing. However, the role of IGLR in the biological process of trauma repair and the probable mechanism of the action remain largely unknown.

AIM OF THE STUDY

To investigate the role of IGLR in the biological process of trauma repair and the probable mechanism of the action.

MATERIALS AND METHODS

The role of IGLR in wound healing was investigated by overall skin wound in mice with Hematoxylin and Eosin (H&E) and Masson trichrome staining. The anti-inflammatory, angiogenesis-promoting and fibril formation effects of IGLR were visualized in wound skin tissue by immunofluorescence staining, and the proinflammatory factors and growth factors were assayed by real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Macrophages, dermal fibroblasts, and endothelial cells were cultured to measure the direct/indirect interaction effects of IGLR on the proliferation and migration of cells, and flow cytometry was employed to assess the role of IGLR on macrophage phenotype. Network pharmacology combined with Western blot experiments were conducted to explore possible mechanisms of the actions.

RESULTS

IGLR increased the expression of CD206 (M2 markers) through the RAS/p38 MAPK/NF-κB signaling pathway during wound injury in vivo and in vitro. IGLR suppressed the inflammatory cytokines iNOS, IL-1β and TNF-α in the early stage of wound healing. During the proliferation step of wound repair, IGLR promoted angiogenesis and fibril formation by increasing the expression of VEGF, CD31, TGF-β and α-SMA in wound tissue, and similar results were verified by RT-PCR and ELISA. In a paracrine mechanism, the extract promoted the proliferation of dermal fibroblasts, and endothelial cells were founded by the conditioned medium (CM).

CONCLUSION

IGLR induced M2 macrophage polarization in the early stage of wound healing; in turn, IGLR played a key role in the transition from inflammation to cell proliferation during the biological process of wound healing.

Clinical significance of focal adhesion kinase (FAK) in cervical cancer progression and metastasis

Focal adhesion kinase is a non-receptor, tyrosine kinase of cells whose key functions are cell adhesion, migration, and invasion. Aberrant expression and regulation of FAK-mediated intracellular signaling pathways has been reported in several cancers and they are involved in cancer cell migration and apoptosis resistance. By RT-PCR, we found that cervical cancer cells showed a 4-fold increase of relative mRNA expression of FAK compared to control cells. In parallel, the FAK protein expression level was also elevated in cervical cancer cells. Interestingly, knockdown of FAK in cervical cancer cells showed attenuated cell proliferation and migration. Further, the FAK RNAi cells became more sensitive to chemotherapeutic drugs such as 5-FU and docetaxel and therefore the rate of cell survival is declined. The significant over-expression of FAK in cervical cancer cells might involve in cervical carcinogenesis and prolonged cell survival. This FAK overexpression might be a potential target for anti-cancer drugs to attenuate rapid cell proliferation and invasion by inducing apoptosis.

Involvement of Rho-associated coiled-coil kinase signaling inhibition in TGF-β1/Smad2, 3 signal transduction in vitro

AIM

To research the effect of Y-27632, a selective Rho-associated coiled-coil kinase (ROCK) inhibitor, on TGF-β1/Smad2, 3 signal transduction in ocular Tenon's capsule fibroblasts (OTFs).

METHODS

Primary ocular Tenon's capsule fibroblasts had been cultured in vitro. The effect of Y27632 on proliferation of OTF stimulated by lysophosphatidic acid (LPA) was evaluated by MTT colorimetric assay so as to sift out the proper concentrations range of Y-27632 for the next experiment. Real time-polymerase chain reactor (RT-PCR) was to analyze the changes of Smad2 and Smad3 genes of cells affected by Y-27632, though unaffected by transforming growth factor-beta1 (TGF-β1). Proteins of Smad2, Smad3, phosphorylated Smad2 (Ser245/250/255), and phosphorylated Smad3 (Ser423/425/203) were respectively quantified by Western blot after OTFs were successively incubated by TGF-β1 and Y-27632. Meanwhile, α-smooth muscular actin (α-SMA) protein was also quantified after the small intervening gene fragments of human Smad2 and Smad3 were designed, synthesized, and then transfected to OTFs.

RESULTS

Y-27632 significantly inhibited OTFs proliferation stimulated by LPA. Also Y-27632 significantly suppressed the expressions of Smad2 mRNA, Smad2, 3 proteins expressions, Smad3 phosphorylation at the carboxylic terminals of Ser423/425/203 which had been radically promoted by TGF-β1. SiRNA-Smad2, 3 suppressed α-SMA expressions, but less effectively than Y-27632.

CONCLUSION

The inhibition of ROCK signaling may be a potential therapeutic candidate for the treatment of the filtration channel fibrosis.

Modulation of Fibroblasts in Conjunctival Wound Healing

Modulating conjunctival wound healing has the potential to improve outcomes after glaucoma filtration surgery and for several ocular disorders, including ocular cicatrial pemphigoid, vernal keratoconjunctivitis, and pterygium. Although anti-inflammatories and antimetabolites have been used with success, these nonspecific agents are not without their complications. The search for novel and more targeted means to control conjunctival fibrosis without such limitations has brought much attention to the regulation of fibroblast proliferation, differentiation, extracellular matrix production, and apoptosis. This review provides an update on where we stand with current antifibrotic agents and outlines the strategies that novel agents use, as they evolve from the bench to the bedside.

Brimonidine reduces TGF-beta-induced extracellular matrix synthesis in human Tenon's fibroblasts

Background

Brimonidine is a highly selective α₂ adrenergic agonist that has been widely used in anti-glaucoma eyedrops. The aim of this study was to investigate its putative anti-fibrotic role in the fibrosis caused by activated Tenon’s fibroblasts.

Methods

Primary cultured human Tenon’s fibroblasts were exposed to 2.0 ng/mL of transforming growth factor-β1 (TGF-β1) for up to 48 h. In the presence of various concentrations of brimonidine (from 0.0 to 10.0 μM), the expression levels of fibronectin, collagen types I and III, and β-actin were determined by Western immunoblots. The expression of phosphorylated SMAD2/3 (p-SMAD2/3) was then evaluated using immunofluorescence.

Results

TGF-β1 significantly increased the synthesis of fibronectin and collagens in human Tenon’s fibroblasts; however brimonidine treatment distinctly attenuated the TGF-β1-induced production of extracellular matrix (ECM) proteins. TGF-β1 also changed the cellular morphology to be plump, while brimonidine treatment returned the cells to a spindle shape, similar to control fibroblasts. Regarding p-SMAD2/3, brimonidine treatment did not show any apparent changes in its expression.

Conclusions

Our data revealed that brimonidine reduces TGF-β-induced ECM synthesis in human Tenon’s fibroblasts in vitro. This finding implies that topical administration of brimonidine may be helpful in reducing the fibrosis caused by the long-term use of topical anti-glaucoma medications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-015-0045-8) contains supplementary material, which is available to authorized users.